#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, a, b) for (int i = (a); i >= (b); i--)
#define endl '\n'
const int N = 2e5 + 5;

mt19937 mt(chrono::steady_clock::now().time_since_epoch().count());
int n, m;
int a[N];
bool solve() {
  cin >> n;
  rep(i, 2, n - 1) cin >> a[i];
  rep(i, 2, n - 3) {
    if (a[i] == 1 && a[i + 1] == 0 && a[i + 2] == 1) return false;
  }
  return true;
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int t;
  cin >> t;
  while (t--) cout << (solve() ? "YES\n" : "NO\n");
  return 0;
}